Abstract: Low-light-level night vision technology is an important component of modern optoelectronic technology that significantly enhances human visual perception through physical processes such as photoelectric image conversion, enhancement, processing, and display. InGaAs semiconductor photocathodes have a high responsivity and electron mobility in the near-infrared band. Thus, they are widely used in infrared detection, high-speed optoelectronic devices, optical communications, and other fields. This paper presents a systematic review of the research progress on InGaAs photocathodes. Focusing on three core physical processes, i.e., photon absorption, electron transport and electron emission, it summarizes the state-of-the-art research and outlines the future development trends. Future studies will concentrate on key technologies including material epitaxial growth, doping modification and micro-nano optical-field manipulation, to continuously optimize the photoelectric emission performance and quantum efficiency, and further expand the application prospects of InGaAs photocathodes in cutting-edge fields such as infrared detection and short-wave infrared low-light imaging.